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<TITLE>Gzip User's Manual - 6. Using gzip on tapes</TITLE>
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<H1><A NAME="SEC9" HREF="gzip_toc.html#TOC9">6. Using <CODE>gzip</CODE> on tapes</A></H1>
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When writing compressed data to a tape, it is generally necessary to pad
the output with zeroes up to a block boundary. When the data is read and
the whole block is passed to <CODE>gunzip</CODE> for decompression,
<CODE>gunzip</CODE> detects that there is extra trailing garbage after the
compressed data and emits a warning by default. You have to use the
<SAMP>`--quiet'</SAMP> option to suppress the warning. This option can be set in the
<CODE>GZIP</CODE> environment variable, as in:



<PRE>
for sh:    GZIP="-q"  tar -xfz --block-compress /dev/rst0
for csh:   (setenv GZIP "-q"; tar -xfz --block-compress /dev/rst0)
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<P>
In the above example, <CODE>gzip</CODE> is invoked implicitly by the <SAMP>`-z'</SAMP>
option of GNU <CODE>tar</CODE>.  Make sure that the same block size (<SAMP>`-b'</SAMP>
option of <CODE>tar</CODE>) is used for reading and writing compressed data on
tapes.  (This example assumes you are using the GNU version of
<CODE>tar</CODE>.)


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